2717c6b649
When a PTE is updated in the page table, the _PAGE_NEWPAGE bit will always be set. And the corresponding page will always be mapped or unmapped depending on whether the PTE is present or not. The check on the _PAGE_NEWPROT bit is not really reachable. Abandoning it will allow us to simplify the code and remove the unreachable code. Reviewed-by: Benjamin Berg <benjamin.berg@intel.com> Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20241011102354.1682626-2-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
59 lines
1.9 KiB
C
59 lines
1.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
/*
|
|
* Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
|
|
*/
|
|
|
|
#ifndef __UM_TLBFLUSH_H
|
|
#define __UM_TLBFLUSH_H
|
|
|
|
#include <linux/mm.h>
|
|
|
|
/*
|
|
* In UML, we need to sync the TLB over by using mmap/munmap syscalls from
|
|
* the process handling the MM (which can be the kernel itself).
|
|
*
|
|
* To track updates, we can hook into set_ptes and flush_tlb_*. With set_ptes
|
|
* we catch all PTE transitions where memory that was unusable becomes usable.
|
|
* While with flush_tlb_* we can track any memory that becomes unusable and
|
|
* even if a higher layer of the page table was modified.
|
|
*
|
|
* So, we simply track updates using both methods and mark the memory area to
|
|
* be synced later on. The only special case is that flush_tlb_kern_* needs to
|
|
* be executed immediately as there is no good synchronization point in that
|
|
* case. In contrast, in the set_ptes case we can wait for the next kernel
|
|
* segfault before we do the synchornization.
|
|
*
|
|
* - flush_tlb_all() flushes all processes TLBs
|
|
* - flush_tlb_mm(mm) flushes the specified mm context TLB's
|
|
* - flush_tlb_page(vma, vmaddr) flushes one page
|
|
* - flush_tlb_range(vma, start, end) flushes a range of pages
|
|
* - flush_tlb_kernel_range(start, end) flushes a range of kernel pages
|
|
*/
|
|
|
|
extern int um_tlb_sync(struct mm_struct *mm);
|
|
|
|
extern void flush_tlb_all(void);
|
|
extern void flush_tlb_mm(struct mm_struct *mm);
|
|
|
|
static inline void flush_tlb_page(struct vm_area_struct *vma,
|
|
unsigned long address)
|
|
{
|
|
um_tlb_mark_sync(vma->vm_mm, address, address + PAGE_SIZE);
|
|
}
|
|
|
|
static inline void flush_tlb_range(struct vm_area_struct *vma,
|
|
unsigned long start, unsigned long end)
|
|
{
|
|
um_tlb_mark_sync(vma->vm_mm, start, end);
|
|
}
|
|
|
|
static inline void flush_tlb_kernel_range(unsigned long start,
|
|
unsigned long end)
|
|
{
|
|
um_tlb_mark_sync(&init_mm, start, end);
|
|
|
|
/* Kernel needs to be synced immediately */
|
|
um_tlb_sync(&init_mm);
|
|
}
|
|
|
|
#endif
|